Bacteriolysis 139 



the immune serum or amboceptor, and the complement in normal guinea-pig 

 serum are brought into contact in small test-tubes, kept for twenty-four hours 

 in the refrigerator, and the amount of solution gauged by the naked eye supple- 

 mented by microscopical examination of the tissue elements. 



Bacteriolysis. — The first observations upon bacteriolysis were 

 made in 1874 by Traube and Gscheidel,* who found that freshly 

 drawn blood was destructive to bacteria. The matter was pur- 

 sued by numerous subsequent investigators and was explained by 

 Buchner as depending upon alexins. Pfeifferf described the 

 peculiar reaction known as "Pfeiffer's phenomenon." Ehrlich and 

 MorgenrothJ and Bordet§ described the mechanism of cytolysis, 

 explaining the "Pfeiffer phenomenon" and paving the way for 

 future experiments. 



Direct destruction of bacteria by blood-serum and body juices 

 is rare, and occurs only when the serum contains appropriate quan- 

 tities of both factors involved — i.e, amboceptor and complement. 

 For the usual bacteriolytic investigations it is, therefore, necessary 

 to consider three factors: i, The bacteria to be destroyed; 2, the 

 serum furnishing the complement; and 3, the serum furnishing the 

 immune body. 



Technic. — i. The bacteria to be destroyed should be prepared in the form of a 

 homogeneous suspension in physiological salt solution, similar to that employed 

 for making the agglutination tests (g. v.). It is best to use the surface growths 

 from agar-agar, well rubbed upon the side of a test-tube containing the fluid, 

 which is permitted to contact with the mass from time to time by inclining the 

 tube so that the fluid is able to carry away the bacteria as they are distributed. 



If quantitative estimations are to be made, the number of bacteria in the sus- 

 pension must be known or at least a standard quantity must be employed, as 

 the destructive process is a chemical one, in which the destructive agents are 

 themselves used up. 



2. The serum furnishing the complement is a normal serum — that is, the 

 serum from a healthy animal that has undergone no manipulation. The guinea- 

 pig is the animal preferred. 



3. The serum containing the amboceptor or the immune body is obtained 

 from an animal that has been given a high degree of immunization against the 

 bacterium to be destroyed or dissolved. The complement contained in this 

 serum should be destroyed by heating for a short time to ss°C. 



These three having been prepared, an appropriate quantity of the bacterial 

 suspension is placed in a small test-tube, and an appropriate quantity of the 

 diluted normal serum added. To this mixture of two constants varying quanti- 

 ties of the immune serum are added and the tube stood away for twenty-four 

 hours on ice. In alpiost every case it will be found that the immune serum con- 

 tains a great quantity of agglutinating substance, so that the bacteria all fall to 

 ■ the bottom in a short time. This is independent of bacteriolysis. The bacterial 

 destruction is gauged by the disappearance of the bacteria or by their failure to 

 grow when transplanted to appropriate culture media. 



By making the bacterial suspension and complementary serum constant quan- 

 tities (taking care that not too many bacteria be present), one is able to estimate 

 the value of the immune serum. By using the bacterial suspension and a heated 

 immune serum (containing no complement) as constants and varying the addi- 

 tion of complementary serum, one can estimate the respective values of several 

 complementary serums. By using both serums as constant factors and varying 



* "Jahresb. der schles. Ges. f. vaterl. Kultur," 1874. 

 t "Deutsche med. Wochenschrift," 1896, No. 7. 

 t "Berliner klin. Wochenschrift," 1899. 

 § "Ann. de ITnst. Pasteur," 1898, xn. 



